Earth Talker - Reuse, Reduce & Recycle

Recycle Drywall

Drywall, wallboard or gypsum are just a few of the many names this common building material is referred to. The big question surrounding this material is the reason why there is a need for it to be diverted from the landfill.

First, to understand why drywall is banned from the landfill, a look into what drywall is composed of is required. Gypsum is a naturally occurring mineral; it is composed of calcium sulphate (CaSO4) and water (H2O). Gypsum is mined from deposits formed by ancient seabeds.

If gypsum is a naturally occurring mineral then why can it not be sent to the landfill? The problem lies not with the calcium or hydrogen elements but primarily with the sulphur component.

Within a landfill or other construction and demolition dumping sites with drywall, rainwater will begin to dissolve the gypsum and concentrated areas of  sulphate will occur that may contaminate groundwater. High concentrations of sulphate in ground water pose a significant risk to the environment.

Another serious problem that may occur is the result from the biological conversion of dissolved sulphate to hydrogen sulphide (H2S).  H2S is a foul-smelling gas (rotten eggs).  It is produced under wet, anaerobic conditions, such as those that often occur in landfills. The presence of high concentration pockets of hydrogen sulphide gas may be released by landfill workers and can be lethal if inhaled. 

A remarkable characteristic of gypsum is its ability to be recycled again and again into usable products. Some examples include the production of new drywall, an ingredient for Portland cement, and as an additive for agricultural and composting operations. The Drywall collected within the RDN is transported to New Westminster and recycled back into usable wallboard products. Even the paper is re-used in the process and converted to the brown backing on new gypsum products.

Recycle Appliances, Electronics and Gadgets

Appliances, electronics, gadgets and all those other miscellaneous gizmos we have in our homes will all eventually become obsolete, broken or simply unwanted. When that day comes, there is a way to recycle them.

10 months ago, a province wide computer and TV recycling program was launched. Since then, the city of Nanaimo has been diverting over 12 metric tonnes per week of waste TV’s and old computer systems. The program has been very successful and lots of people, businesses and organizations have been taking full advantage of the Electronics Recycling Program.

However, often there is a dead microwave, VCR, toaster, stereo, or even a washer and dryer that continues to sit somewhere in our homes, coffee room or storage area. What can be done with this material? Lots.

This category of waste materials all has a common element of construction, metal.Granted, they may not be 100% metal like the tin can or pie plate. But there is a high enough metal content within them that makes it a valuable recyclable item.

The Landfill and the NRE will accept these items for metal recycling. The electronics are shredded in a large hammer mill and then shipped for smelting. In a controlled environment, these items are heated and the metals are extracted for reuse. The bits of plastic and other non-metal contaminants are incinerated and act as an additional fuel source for the overall smelting process.

My personal take on incineration is that I would rather recycle a given item rather than burn it up and loose it forever. The extraction of new or virgin raw materials from the ground places a greater strain on the environment than processing already available materials, like plastics.

So, when people can take the time to remove plastic from such electronic gadgets, the plastic can then be saved for reuse in a plastics recycling stream. The important thing to remember is that for plastic recycling to work, all metal screws and other non-plastic materials must be removed as these contaminants can really disrupt the plastic shredding process.

Recycle Polycarbonate Plastic

The recent move by the Canadian Government to ban Polycarbonate plastic baby bottles has stirred up a lot of concern over plastic use for food and drink. The attention also prompted some issues over plastic recycling.

There are seven categories of plastics, which are denoted by a number encased within a recycling symbol. The numbers range from #1 through to #7. All have different chemical composition that ultimately determines their use.

The spotlight is on plastic #7 with a PC (polycarbonate) designation beside it. In some cases, all that you will see is “PC”. #7 plastic represents the co-mingle of all the other types of plastics. The addition of PC makes for a lightweight, high-performance plastic that possesses a unique balance of toughness, dimensional stability, optical clarity, and high heat resistance. This is why we see it in so many applications including food containers and utensils.

The scary thing in a PC container is the addition of Bisphenol A (BPA), which is a key building block of polycarbonate plastic. In a food or drink application container, studies have shown the migration of BPA into the food from the container. The big controversy is of course, how much of the BPA is getting into the food and how much do we have to consume before our hormones get all disrupted?

We are not going to answer that here. But lets see how this will effect plastic recycling.

Essentially, there is no change to current plastic container recycling practices. Curbside collection and any depot will still collect #7PC plastics with no questions. The mixed plastics will be shredded up and made into new #7 plastics, some of which may have a PC designation if the manufacture adds a lot of polycarbonate to the #7 mix.

Just for information purposes, the plastics to avoid for food and drink type activities include #3, #6 and #7. The safer plastics to use are #1, #2, #4, and #5. However, there are concerns over reuse of plastic containers and the heating of plastics containing food.